Examine source code of VLC 4

{
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "description": "Open YouTube videos in VLC.",
  "icons": {
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "manifest_version": 2,
  "minimum_chrome_version": "25.0",
  "name": "VLC 4 YouTube (beta)",
  "page_action": {
    "default_icon": "icons/icon-19.png",
    "default_popup": "popup.html",
    "default_title": "Open this video in VLC"
  },
  "permissions": [
    "tabs",
    "webRequest",
    "webRequestBlocking",
    "*://*.youtube.com/*",
    "http://localhost/*"
  ],
  "commands": {
    "_execute_page_action": {
      "suggested_key": {
        "default": "Alt+V"
      }
    }
  },
  "version": "0.4.1",
  "browser_specific_settings": {
    "gecko": {
      "id": "{14c7f1e4-1487-457f-bbac-0c1942cc7fd9}"
    }
  }
}